The calculation is incorrect, because the slope is defined as
So, Emma has inverted numerator and denominator: she has calculated the inverse of the slope.
The correct calculation would be
94x689=64,766
if you round it to the nearest ten you get 90x690=62100
62100 is closer to 60,000 than it is to 70,000.
so you would round it down to 60,000.
It's like saying 6(x+4)=x-11.
3.5 kg:800g
3500g:800g
35g:8g